diff options
Diffstat (limited to 'drivers/tty/serial/8250')
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 66374704747e..e4dd82fd7c2a 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -2696,21 +2696,32 @@ static unsigned int serial8250_get_baud_rate(struct uart_port *port, void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk) { struct uart_8250_port *up = up_to_u8250p(port); + struct tty_port *tport = &port->state->port; unsigned int baud, quot, frac = 0; struct ktermios *termios; + struct tty_struct *tty; unsigned long flags; - mutex_lock(&port->state->port.mutex); + tty = tty_port_tty_get(tport); + if (!tty) { + mutex_lock(&tport->mutex); + port->uartclk = uartclk; + mutex_unlock(&tport->mutex); + return; + } + + down_write(&tty->termios_rwsem); + mutex_lock(&tport->mutex); if (port->uartclk == uartclk) goto out_lock; port->uartclk = uartclk; - if (!tty_port_initialized(&port->state->port)) + if (!tty_port_initialized(tport)) goto out_lock; - termios = &port->state->port.tty->termios; + termios = &tty->termios; baud = serial8250_get_baud_rate(port, termios, NULL); quot = serial8250_get_divisor(port, baud, &frac); @@ -2727,7 +2738,9 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk) serial8250_rpm_put(up); out_lock: - mutex_unlock(&port->state->port.mutex); + mutex_unlock(&tport->mutex); + up_write(&tty->termios_rwsem); + tty_kref_put(tty); } EXPORT_SYMBOL_GPL(serial8250_update_uartclk); |